Question

if xyz=8,find the values of x,y for which u = 5xyz/x+2y+4z
(Maxima and minima of two variables)

Answer 1

Answer:

u =4/5 or 0.8

Step-by-step explanation:

xyz= 8

then...

u= 5xyz/X+2y+4z

u= 5×8/xyz(1+2+4)

u= 40/8×7

u= 40/50

u= 4/5

or u= 0.8

Answer 2

Given:

XYZ = 8

value of u = $\frac{5xyz}{x+2y+4z}$

To Find:

value x and y

Solution:

u = $\frac{5xyz}{x+2y+4z}$ (given)

Now, substituting the value of XYZ in the given equation, the value of XYZ is 8 (given)

⇒ $\frac{5(8)}{xyz(1+2+4}$ = u

⇒ $\frac{40}{8*7}$ = u

⇒ $\frac{40}{50}$ = u

⇒$\frac{4}{5}$ = u or 0.8 = u

Therefore, the value of x and y is 0.8.